Dustproof watch crown



April 15, 1952 R. FEURER 2,592,881

DUSTPRGOF WATCH CROWN Fileld lay 5, 1950 BY al ATIRA/'y Patented Apr. 15, 1952 DUSTPROOF WATCH CROWN Robert Feurer, Jackson Heights, N. Y., assignor to Feurer Bros.,v Inc. ration of New York New York, N. Y., a corpo- Application May 5, 1950, Serial No. 160,227

1 Claim. 1

The invention disclosed in this patent application is a watch crown of dust-tight construction.

Objects of the invention have been to provide a practical, reliable dustproof crown of the simplest form and lowest possible cost of construction.

In accomplishing these desired results, parts have been reduced to a minimum by using a watch case without a pendant tube and by fitting a short length of compressible tubing over the tubular post of the crown and directly pressing at its inner end against the shell of the watch case.

This compressible tubing is suiiiciently elastic to permit the setting movements of the stem without breaking contact with the case, and a beveled incline or shoulder in the crown assures complete sealing of the outer end of the cornpressible sleeve or tubing.

Other detail features of the invention and further desirable results attained are set forth or will appear in the course of the following specification.

The drawing accompanying and forming part of the specication illustrates certain present preferred embodiments of the invention but structure may be otherwise modified and changed within the true scope of the invention as hereinafter defined and claimed.

Fig. l in the drawing is a broken vertical sectional view of a watch case and crown having the invention incorporated therein;

Figs. 2, 3 and 4 are similar views of other, modified forms of the invention.

In the several views a watch case of the tubelesstype is indicated at 5, having an opening 6 for free and clear passage of the winding and setting stem 'I and the tubular post 8 of the crown which is screwed thereon.

The crown, designated 9, is of any usual or preferred form but differs from the ordinary in that it has a relatively deep annular cavity or well I0 therein surrounding the root portion of the tubular post 8.

Further, this deep annular cavity in the inner face of the crown is formed at the back with an inwardly convergent slope, incline or bevel II to form a valve-like sealing face for engagement with the inner end of a compressible sealing sleeve or tube I2 of rubber, plastic or other such suitable material.

This compressible tube is long enough to reach from the back of the cavity in the crown into 2 rotary sealing engagement at I3 with the surface of the case, about the stem opening 6.

Also, it is to be noted that the packing sleeve I2 does not touch the outer cylindrical wall I4 of the crown cavity but does t closely over the tube or post 8 of the crown.

With this construction it is only required that the packing sleeve have a reasonably tight t on the crown tube because this tube is sealed at the inner end by pressure against the wall of the case and sealed at the outer end by engagement with the beveled, valve-like surface II in the back of the crown.

Fig. 2 illustrates a variation over Fig. l in that the outer end of the packing sleeve has a correspondingly inclined bevel seat I5 formed in the outer end to lit the incline of the crown.

In the Fig. 3 form of construction a slight, abrupt angular shoulder I6 is provided at the lower, smaller end of the convergent valve or sealing wall II to provide a more solid shoulder for forcing the packing sleeve firmly against the shell of the watch case.

Fig. 4 illustrates a further development, in which the convergent sealing surface I l is terminated with a reversely sloping, upwardly convergent wall I'I which provides a sharp intermediate lip I8 in biting engagement with the mid-portion of the packing sleeve.

In all forms of the invention the endwise compressible packing sleeve makes sealing engagement at the outer end with the crown and at the inner end directly with the case of the watch and is free intermediate the ends to expand laterally away from the screw post portion of the crown, if that be required by the longitudinal compressive force applied to the sleeve.

The construction is particularly simple and inexpensive and provides a practical, low cost dustproof construction adaptable to all forms of crowns and cases.

The inclined sealing surface at the back of the cavity may .in some instances have a spreading or wedging effect on the outer end of the packing sleeve, particularly in the forms shown in Figs. l, 2 and 3.

What is claimed is:

A dust-proof watch case crown construction comprising, in combination, a tubeless case having a stern opening in the side of the same, a crown having a tubular screw post of less diameter than said opening and extending freely therethrough and out of contact with the case, said crown having a relatively deep, annular cavity therein about the post and an elongated cylindrical packing sleeve of compressible elastic material in close tting engagement about the post and extending continuously from the case into said annular cavity in the crown and forming the only connection between the case and 5 crown, said sleeve bearing at its inner end against the shell of the watch case about said stem opening therein and closing and sealing the space between the case and the screw post extending therethrough, the outer end portion of the sleeve extending into the annular cavity in the crown being free of the surrounding enclosing Outer wall of the cavity'and the outer end of the sleeve being in abutting engagement with the back wall of the cavity and said back wall of the cavity being inclined from one side to the opposite side wall of the cavity and forming an annular inclined bevel surface extending over and in sealing engagement with the outer end of the sleeve.

ROBERT FEURER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 343,576 Evans June 15, 1886 2,237,860 Bolle Apr. 8, 1941 2,482,583 Greenberg Sept. 20, 1949 FOREIGN PATENTS Number Country Date 2,203 Great Britain Jan. 26, 1884 274,788 Great Britain July 28, 1927 160,210 Switzerland May 1, 1933 194,226 Switzerland Feb. 16, 1938 229,461 Switzerland Feb. 1, 1944 

